Into The Underground—Undertale
by vi0dusk
Summary: (Yet another novelization with an oc) The legends said that anyone who climbed the mountain never returned. Down in the abyss, monsters supposedly dwell in the caverns, their large mountain prison. So why did she climb the mountain? Was it immaturity, foolishness? Fate...? If she hadn't, then perhaps monsters would still be trapped in the loneliness of the Underground.
1. Prologue

_Long ago, two races ruled over earth: humans and monsters. They lived in peace for a great while, but as you may know, all great things may come to an end one day._

_The humans attacked and declared war against the monsters, and they did so mercilessly. But it wasn't necessarily for power, for the humans already had a great amount of it -- they attacked because of their own fears._

_Monsters are made of magic. A monster's physical matter and their SOUL are closely linked, so when a monster dies, their body turns to dust, and their SOUL disappears quickly, becoming lost forever. But, for this special race, there is an exception. Boss monsters. A boss monster's SOUL is stronger than the average monster soul, and does not immediately disappear -- it will persist after the boss's death, yet only for a few moments._

_But a human's SOUL? A human's soul is not the entirety of their body, but rather their essence housed in a physical body. This lets a human SOUL persist longer, even after death._

_This gives monsters an advantage. A monster can absorb a human SOUL, but a human cannot absorb a monster soul as easily without a great power. A monster lucky enough to absorb a human SOUL, comes with a reincarnation, one may say, into a beast with unfathomable powers._

_This power, this advantage was what the humans had feared._

_Not a single human SOUL had been taken in war, but countless monsters were dusted. The humans came out victorious, and seven of their greatest magicians sealed monsterkind into the underground. It is possible for maybe anyone to enter the seal, perhaps one with a strong SOUL, but it would take the power of two SOULs—a human's SOUL and a monster's SOUL—to exit._

_But... all of that is just a legend, right?_

Curiosity was something that always seemed to get the best of anyone when it came to the forest that surrounded Mt. Ebbott. From time to time, trekking up the mountain was the first idea campers had when they arrived on site. It made for a peaceful pastime until the mountain got too steep and they'd be forced to hike back down with caution.

The occasional camper, however, knew there was more to the mountain than a hike—the history behind the mountain, with legends of another race banished long ago, lured the risk takers and researchers out to the woods who longed for the thrills of life and more learning.

Today, the occasional camper was a mix.

Gazing up as she reached a clearing, a young girl evaluated an estimation of time it would take to reach the top. With each cautious step away from the tall forms of bark, anxiety and exhilaration twisted together in her guts as she recalled the treacherous stories—anyone who climbed the mountain never returned.

Within the first few steps up the mountain, her mind filled up with second thoughts. She proceeded cautiously, warily looking as the bumpy trails only got steeper.

As the exhilaration took over when she was able to look over miles of trees, she looked down to notice black abyss below her, and the short-lived exhilaration was quickly replaced with new nausea and anxiety. She was so far, though—she had to fight on with determination and perseverance.

That proved to be a horrible idea, as she found herself falling into a patch of gold before her vision was lost.


	2. Ch 1: Flowers

"Oh! You've fallen down haven't you? Here, get up. What's your name?"

...

"C̷̵̶̀͝h̸a̷͞r̸̀͟a̶͘͘͞? That's a nice name. My

name

is..."

~•~

Wake up, Katelyn—you're the future of humans and monsters, now. You have a journey to fulfill now. Stay determined.

Weakly, I slowly look at my surroundings when my eyes open to bright yellows and golds. With nearly no strength, I attempt pushing myself up so at least my face is off of the ground.

I immediately retract my actions and collapse back down when unbearable pain shoots through my arms. With caution, I slowly attempt sitting up and scan the whole area, aside from the bed of flowers that I'm apparently sitting in. Everything is dim.

As I try to recall what had happened, it dawns on me like a truck.

I fell down.

That only leaves me with one question... how am I still alive?

I feel around my back for the backpack that was there before. Unsurprisingly, it's gone, and I have no way of getting food, water, or my phone. Thanks, mountain...

A doorway beckons for me at the end of the cavern. If I can't climb back up, which I obviously can't unless falling gave me miraculous flying powers, then going further into the cavern is my only bet.

Any attempt to get up is shot back down with hisses of pain. My body aches everywhere, and there are most likely bruises everywhere. To be clear, I roll up a sleeve, and unsurprisingly, half of my arm is a purple mess. If anything is really bad, then I have broken bones at least somewhere.

With no way to nurse any aches, any hope for survival is lost. With force, I stand up, wincing at the pressure in my legs. With a limp, I slowly but surely move towards the arched doorway.

Further into the realm of so called monsters from the war in legends. If the legends happen to be true...

Well, goodbye world. Tell school that if you're going to give us badges for door access, at least let us use them and stop disallowing student access for 99% of them.

Past the doorway, it's even darker than before, but a single dimmed ray of light pierces through the rocks, illuminating a patch of grass like a spotlight. Ignoring my numbing legs, I walk forwards. On top of the tiny hills sits a yellow flower, appearing wilted but swaying slightly. My conscience tells me that I should back away... but it's a flower. It's practically harmless, and no one ever listens to their inner voice, right?

With a few more steps, it suddenly raises from its wilted form, revealing its white center as it faces me as if I were the sun.

"Howdy!"

When I hear a small, high-pitched voice, I gasp and fall backwards.

I must be going insane.

"The flower speaks," I hoarsely mutter to myself in shock.

More to my surprise, it mutters under its breath, "obviously."

A tense silence lingers for a few seconds. "Hmm," it says, "you're new to the Underground, aren'tcha?"

"U-Underground...?"

For a split second, I swear that a mischievous expression hangs over its face, but quickly returns to its overwhelming smile. I can't put my finger on what it is, but something isn't right.

"Golly, you must be so lost and confused," it mused, overly sympathetic and cheerful.

"Um... y-yeah-"

"Someone ought to teach you how things work around here. I guess little old me will have to do," it says, "ready? Let's go!"

Cued with his words, a small, red glow shines at my chest, where a red heart glows in contrast against my black coat.

"See that little red heart? That is your SOUL, the very culmination of your being!"

In confusion, yet amazement, I stare at the so-called SOUL. To think that I've never seen this before and it came right out of my chest, it's strange.

But it's beautiful. "That... is really cool...!"

"Yes, isn't it? Your soul starts off weak, but can grow stronger if you gain a lot of LV. What's LV, you may ask?"

I take the most logical guess. "Uh... lev- levels?"

He stares at me, as if I were an idiot.

"Level? Of course not, silly! This isn't a game. LV stands for LOVE, of course!"

If you expected any person to guess that when you ask, then you must be a lost cause. "Riight.."

"Now... you want some LOVE, don't ya?"

I dunno_ Flowery_, do I?

"I don't know," I joke, "do I...?"

_His over-cheeriness is scaring me and getting on my nerves._

"Don't worry, I'll share some with you!"

He winks, leaving me unnerved. An arc of white ovals appear above him, which only adds to my fear. Not only is it a talking flower, but it has magical abilities—so all I can do is take caution.

"Down here, LOVE is shared through.. little white.. friendliness pellets!"

_Friendliness pellets._

Not only is that name stupid for something so potentially threatening, but it's so hard to contain my laughter as I do so silently in my head.

"Right," I stifle a laugh, "I got it... friendliness pellets.

"Are you ready?" he chirps, "move around, catch as many as you can!"

The little white pellets fly slowly towards my soul, sending a spike of nausea through my stomach with each inch towards me. Out of a rising panic, I abruptly jerk myself to the side; the pellets pass straight through my body, even more unnerving than all of the previous events combined.

Flowey's expression shifts to one of irritation. "Hey buddy," he chides, "you missed them. Let's try again!"

A new arc of pellets repeats the actions of the previous set. Even more unsure than before, I dodge them again. They barely miss me. His face turns even more annoyed—my actions seem to be annoying him.

_*"You think?"_

A high-pitched voice rings through my head, causing my hand to shoot up to my forehead. As if something were trying to possess me.

_*"The soulless flower is _very_ agitated now."_

"Is this a joke?" he berates, "are you braindead? RUN. INTO. THE. BULLETS- friendliness pellets!"

With much more speed, he throws another round of tiny pellets at me that I can't dodge. Immediately after contact with my soul, an indescribable pain leaves me unable to move. The sharp pain in my chest is as if someone suddenly stabbed me. Though already on the ground, I collapse even more, my head making contact with the cold ground. Even if I don't show physical signs of damage from the damage to my soul, my whole body feels as if it's on fire.

"You idiot," he cackles. His face contorts into an expression straight out of a good horror movie, and I choke back a sob of fear. Combined with the pain, I've lost all hope of survival.

"..._why_?" That's all I manage to gasp out.

"In this world, it's kill or _BE_ killed. Why would _anyone_ pass up an opportunity like _this_?"

A circle of pellets—bullets—surround me completely. I make no attempt to try and escape, because frankly, it would only make the pain worse.

As the bullets follow my every movement, leaving me completely vulnerable, I choke back an urge to scream. _I can't die, no, I'm only fifteen. Death is never something anyone should have to worry about, and I especially can't die to a flower._

At my feet rests a yellow, but mostly red bar reading _01/20 HP. _Something straight out of a video game.

"_DIE_!"

With his still terrifying face, that sadistic face that shows how much he enjoys my suffering, he cackles evilly while the white arc of bullets inches closer and closer to my exposed soul. I let out a final yell before I close my eyes, waiting for my impending doom.

_Good job... Kate, you are a goner._


End file.
